Temperature controlled heater and enclosure therefor



M. B. wLcox 3,011,771

TEMPERATURE CONTROLLED HEATER AND ENCLOSURE THEREFOR Dec. 5, 1961 2Sheets-Sheet 1 Filed Feb. 23, 1960 INVENTOR MERR/44 B. h//Lcox lrrmvsysM. B. WILCOX Dec. 5, 1961 TEMPERATURE CONTROLLED HEATER AND ENCLOSURETHEREFOR Filed Feb. 23, 1960 2 Sheets-Sheet 2 INVENTR.

x o c m 3 I u R M United States Patent O 3,011,771 TEMPERATURECONTROLLED HEATER AND ENCLO'SURE THEREFOR Mer-fill B. Wilcox,Minneapolis, Minn., assignor to Aladdin Manufacturing Company,Minneapolis, Minn., a

cerporation of Minnesota Filed Feb. 23, 1960, Ser. No. 10,402 8 Claims.(CI. 263-2) The invention herein presents a ther-mostatically controlledheating device and an insulated box used one inside of the other tocomprise a portable heated enclosure.

In commercial practice it has become desirable to use certain liquidmaterials which when combined with proper catalytic agents solidify toform a relatively hard material capable of maintaining a molded shapeand which are readily adaptable to usage in certain phases of publicutility Operations. To function properly such liquid materials should bemaintained at temperatures between 75 and 80 F., which is, for a majorpart of the year well above the ambient outdoor temperature in thenorthern parts of the nation where outdoor temperatures well below thezero degree mark are not uncommon. Further, said liquid materials areoften canied in trucks or other commercial 'vehicles to the job site foruse. Temperatures within such vehicles vary greatly.

Said liquid materials are often sealed in flexible, easily rupturable,heat destructable plastic containers which cannot be subjected to high,direct heat without container failure and consequent liquid loss.

The heated box is used, for example, by telephone company servicemen forkeeping liquid plastic materials at a predetermined temperature so thaton the job the material may be molded to form line connector blocks orsimilar small nonconductive parts used in the maintenance of telephonelines. The box and heater operate to keep the liquid at an eventemperature so that it is instantly used whenever a part must be moldedvto complete an installation.

In a device made according to the present invention, the heat outputsupplied to the inside of an insulated box from a fuel burning heaterlocated therein is regulated by thermostatically controlling the rate ofair flow past the burner of said heater.

Said heater output is transmitted from said heater (l) by conductionalong fins integral with and extendiug outwardly from said heater, andfrom said fins into and throughout an air permeable partition in contactwith said fins 'and dening a heater confining area; (2) by convectiondue to air currents throughout the box; and (3) by radiation from saidheater, fins and partition.

For use in the present invention, a catalytic type warmer i of thegeneral type described in U.S. Letters Patent No.

2,670,728 but with an added thermostatic control has been found to beentirely satsfactory.

An object of the invention is to provide a heated, insulated box thatcan be readily transported by hand and placed in a truck or othercommercial vehi'cle so the contents are available at the propertemperature for use on the job site during the normal work day.

In the drawings,

FIG. 1 is a top plan view of a heating device of the presentnventionshowing a relative position of a thermostatic control;

FIG. 2 is a side elevational view of said heating device showingradiatng vanes and their relative spacing;

FIG. 3 is a detailed sectional view taken on the line 3-3 in FIG. 1 withparts in section and parts broken away;

FIG; 4 is a detaled sectional view taken on the line 4 t4 in FIG. 3;

FIG. 5 is a perspective view of an insul-ated, heated box of theinvention showing the relative position of said heating device and ofmaterial to be kept at an even temperature;

FIG. 6 is a sectional view of said box and heating device taken on the,line. 6-6vin FIG. 5.. with the box cover in place;

FIG. 7 is a perspective View of one type of container that can be keptat a constant temperature within the insulated box; and

FIG. 8 is an enlarged fragmentary' sectional view oi a portion of thedevice as seen in FIG. 3. V

Refern'ng to the drawings and the numerals of reference thereon, asuitable heating device 10 comprises a fuel tank 11 filled withabsorbent material 12 which is impregnated with liquid fuel, and abu-rner unit '13 mounted on a top wall 14 of the tank 11. The burner 13is above an opening 19 in said top wall and is spaced from and adjacentthe impregnated absorbent material 12 through said opening. Said burnerunit will be operative by reason of heat of combuston to cause vaporzedfuel continuously to emanate from said. absorbent material and theburner unit will utilize the fuel. which it vaporizes to. sustaincombustion.

An elongated, circular wick 15 is embedded into the impregnatedabsorbent material and extends upwardly through the top wall 14 of thelower tank 11 to be adjacent to said burner unit. This wick. will beimpregnated with liqud fuel from the absorbent material by' means ofcapillary -attractiom A ame applied to the wick will cause combustion tobe initiated in the burner.

A cover cap 16 is removably fitted upon the upper end of fuel tank 11and comprises a top wall 17 and spaced, side walls 20, 20 equipped withvent holes 21. Said cover cap and said lower tank each have a pluralityof arallel, outwardly extending fins or vanes 18 to dissipate andradiate heat from the heater. Top wall 17 of cover cap 16 has a centerhole 22, and a flue hole 23 shaped like v a segment of an annular ringconcentric with and spaced from said centerhole.

A thermostatic unit 24 comprises =a bi-metallic element 25 wound as aspital which is fixedly attached at its center point to a control stud26 and which is connected at its outermost end, to an ear 27 which earis integral with and perpendicular to the outer periphery of a substantially circular damper plate 30; Said damper plate 30 hasa hole 31at its center, and has hole 32 similar in shape and size to flue hole 23and located in the same relation to hole 33 of said damper plate as saidflue hole 23 is located in relation to center hole 22 in, top wall 17.Control stud 26 extends freely rotatably outward through said hole 31 ofdamper plate 30 and through center' hole 22 in said top wall 17. Damper.plate 30 is spaced slightly downward from top wall 17 and upward fromthe spital bi-metallic element 25, by shoulders 33 and 34 respectivelyon control stud 26. Said damper plate being constrained to rotate abovesaid control stud in response to move ments of the outward end of saidspital bi-metallic ele ment.

At one end of hole 32 in said damper plate is a stop ear 35 whichprotrudes upwardly from said' damper plate through sadflue hole 23 inthe top wall 17 to limit the travel of the damper plate to, that segmentof a circle described by said flue hole 23. At one limit of travel, fluehole 23 and damperhole 32 will be substantially in overlying, alinedrelationship,w providing a passageway for air; at the other end oftravel said flue hole will be substantiaily covered by a solid portionof said damper plate. The area of fine. hole 32 which, may be uncoveredbetween the two above described. limits. is infinitely variable.

A fiction type Washer 36 is located in surrounding relationship to saidcontrol stud 26 between the top wall 3 17 and the control knob 37 whichis fixedly attached to that portion of said control stud which protrudesabove said top wall, thus to insure that the control stud will bemaintained in fixed angular relationshipwith respect to said cover capas determined 'by manipulation of said manual control knob 37.

An insulated, compartmental box 41 comprises spaced, parallel side walls42, 42 spaced, parallel end walls 43, 43, spaced, parallel bottomwall 44and top cover 45. Said walls and the cover are made of a rigid materialof relatively low heat conductivity. By way of example expandedpolystyrene walls covered on the outside with a fibrous, rigid, airtightplastic skin and lined on the inside with tin foil have been found to beexcellent. As shown, the top cover 45 and one end wall 43 are eachprovided with a pair of breather holes 46, 46. Since these breatherholes 46, 46 are on faces of the box at 90 to each other, it followsthat one pair will always be above the other as long as the box ispositioned on a horizontal surface. The -tendency for hot air to riseinside of the box will cause an outfiow through the higher flow ofbreathers and a consequent inow of air through the lower thus to providesufficient fresh air to support combustion. The size of the opening,however, is sufiiciently restricted `to have no appreciable eifect onthe internal temperature of the box.

The top cover 45 is remo'vably tted at the upper edge of the 'w'alls 42,42 and 43, 43, and is positioned between them by a shoulder 47 so thatwhen the cover is in place, the joint between the walls and cover willbe substantially airtight. The heating device previously described ispositioned in one end of the box 41. A divider screen or partition 50having relatively high heat conductivity is constructed to allowsubstantially unrestricted air movement therethrough, is locatedadjacent and contiguous to the fins 18 of said heating device li? andprevents a heat destructble plastic container 51 which encompasses thematerial 53 to be heated from coming in to direct contact with the fueltank or the cover cap of the heating device. This partition 50 alsoserves as a means for further dissipating heat from the burner to theatmosphere within the box. A thermometer 52. is located in the top cover41 to indicate the arnbient temperature within the box. v

FIG. 7 llustrates one type of container for storing liquid material forwhich this box and hcater unit was designed. The disclosure comprisesthe sealed, flexible, heat destructible plastic contaner 51,substantially filled with liquid 53 which must be at a temperature ofbetween 75 and 80' F. at the time t is used. When this liquid is pouredinto a mold or other form and suitable Catalyst added, it solidifiesinto the shape defined by said mold and is then suitable to' perform itsultimate intended use.

The heating device 10 can be removed from the box so that a volatileliquid fuel can be poured into the lower tank 11 and the wick will thenbe ignited by placing a ame to it with the cover cap removed. Asexplained above, the liquid fuel will be drawn upwardly through the wickso that the wick will continue to flame. After the burner has beensufliciently heated by the wick to support and sustain combustion, thecover cap will be replaced, thus extinguishing the wick. The controlknob 37 will then be adjusted so the pointer 38 is set to the desiredheat level as shown by indicia 40 on said cover cap top wall 17. Theflue hole 23 through the top wall of the cover cap and hole 32 throughthe damper plate will be substantially coincident and alined when theunit is cold and is first ignited.

Heat emanating from the burner will set up a convection current bytaking in cool air through the side holes 21, which are below the burnerand discharging heated air, which tends to rise, through the passagewayprovided by hole 32 and fiue hole 23 in the damper plate and top wall ofthe cover cap respectively.

The cover cap and lower tank will conduct heat away from the burner tothe parallel vanes 18. Sad vanes are of relatively greater area and willrapidly radiate the heat to the surrounding atmosphere and to passingconvecton air Currents.

As combustion continues the ambient temperature within the cover capwill rise, causing the spiral bimetallic strip to expand. This willcause its constrained outward end, which is fastened to ear 27 to movein a substantially circular motion and in turn cause the damper plate 36to rotate about the control stud 26. As the damper plate rotates, fluehole 23 and damper hole 32 no longer coincide and ilue hole 23 becomespartially covered by a solid portion of the damper plate. This restrictsthe convection flow of air across the burner, slows the rate ofcombustion, and reduces the amount of heat produced or generated by theburner.

'Ihe transfer of heat through the integral vanes to the surrounding aircontinues and the ambient temperature at the thermostatic unit isreduced. This causes the spral bi-metallic strip to contract, uncoveringa greater portion of the flue hole 23 and again increasing the rate of'combustion. This action occurs during minute differentials oftemperature so that substantially a uniform amount of heat is producedor generated by the burner at any particular setting of the controlknob.

It should be noted that vent holes 21 are of such size and arrangementso .they allow sufiicient exchange of air to support burner combustionat a reduced rate and so that at no time will the burner becomeextinguished due to lack of oxygen, even if the fiue hole 23 is fullycovered by damper plate 24.

With the heating device 10 in the insulated box 41 so that the screendivider or partition is in contact with the fins and is separating theheater, and with the cover 45 in place, heat from the vanes 18 will beradiated to the surrounding air and will be conducted to the partition50 and throughout that partition. The air inside of the box willcirculate from normal convcction currents, illustrated generally by thearrows 54 in FIG. 6, thereby maintaining a substantially uniforrntemperature throughout the interier of the box 41.

What is claimed is:

1. A temperature controlled heater including a fuel tank having anopening in a top end thereof, liquid fuel impregnatable absorbentmaterials substantially filling said tank, a burner to burn fuel vaporsfrom said tank opening Situated in spaced, overlyingvrelation to saidtank opening, a cover mountcd on said tank and encompassing said burner,said cover being provided with air entrance and combustion productegress openings, a damper plate pivotally mounted with respect to saidcover and having a damper opening therethrough, an ear fixedly attachedto said damper plate and projecting through said egress opening, saiddamper plate being moveable between a first position in which saiddamper opening and said egress opening are in alined relationship toeach other and a second position in' which said damper platesubstantially blocks said egress opening, and means operative to movesaid damper plate between said first and said second position responsiveto the temperature of said heater.

2. The combinaton as specified in claim 1, a portable insulated boxenclosing said heater, and means within said box constituted as an airpermeable partition providing within said box a heater conning area anda temperature controlled storage area;

3. The combination as specified in claim l wherein said means forcontrolling said damper includes a stud manually rotatable with respectto said cover, and a bi-metallic element mounted at a first end thereofto said stud, said damper being rotatably m'ounted With respect to saidstud and fastened to a second end of said bi-metallic ele ment. a

4. A temperature controlled heater including a fuel tank having anopening in a top end thereof, liquid fuel impregnatable absorbentmaterials substantially filling said tank, a burner to burn fuel vaporsfrom said tank opening Situated in spaced, overlying relationship tosaid tank opening, a cover having side Walls mounted on said tank and atop wall, said cover encompassing saidburner, at least one of said sidewalls having an air accew opening therethrough and said top wall havingan egress opening therethrough; a damper plate mounted with respect tosaid cover and having a damper opening therethrough, said damper platebeing movable between first position in which said damper opening andsaid egress opening are in alined relationship with each other to permitunobstructed passage of the products of combustion from said burner tooutside of said heater and a second position in which said damper plateprevents substantial flow of said combustion products through saidegress opening, temperature controlled means operative to move saiddamper plate between said first and second positions, a plurality ofbeat conduction fins integral with and extending outwardly from saidheater, a portable insulated box enclosing said heater, and means withinsaid box constituted as an air permeable partition of relatively highheat conductivity providing within said box a heater confining area anda temperature controlled storage area, said partition being inContacting, heat conducting relationship to at least some of said fins.

5. The combination as specified in claim 4, wherein said box is providedwith at least two breather holes open from outside said box to insidethereof, said holes being Situated to normally lie in spaced, verticalrelationship with respect to each other.

6. A temperature controlled heater including a fuel tank having anopening in a top end thereof, liquid fuel impregnatable absorbentmaterial substantially filling said tank, -a burner to burn fuel vaporsfrom said tank opening situated in spaced, overlying relationship tosaid tank opening, a cover having side walls mounted on said tank and atop wall, said cover encompassing said burner, at least one of said sidewalls having an air access opening therethrough and said top wall havingan egress opening therethrough, a damper plate mounted with respect tosaid cover and having a damper opening therethrough, said damper platebeing movable between a first position in which said damper opening andsaid egress opening are in aligned relationship with each other topermit unobstructed passage of the products of combustion from saidburner to outside of said heater and a second position in which saiddamper plate prevents substantial flow of said combustion productsthrough said egress opening, a control stud frictionally rotatablymounted through said top wall of said cover, a spiral Wound bi-rnetallicele ment fixedly mounted at an inner end thereof to said stud, and amanual control knob integral with said control stud outside of saidcover, said damper plate being freely rotatably mounted on said stud andfastened to an outer end of said bi-metallic element.

7. The combination as specified in claim 6, and a plurality of heatconducting ns integral with and extending outwardly from said heater.

8. The combination as specified in claim 6, a potable nsulated boxenclosing said heater, means within said box constituted as an airpermeable partiton of relatively high heat conductivity providing withinsaid box a heater confining area and a temperature controlled storagearea, said partition being in Contacting, heat conducting relationshipto said heater, and wherein said box is provided with at least twobreather holes open from outside said box to inside thereof, said holesbeing Situated to normally lie in spaced vertical relationship withrespect to each other.

References Cited in the file of this patent UNITED STATES PATENTS273,757 Morel Mar. 13, 1833 945302 Brown Jan. 4, 1910 1,659,875 JacobsFeb. 21, 1928 2,458,837 Dougherty Jan. 11, 1949 2,670,728 Smith Mar. 2,1954 2,780,28O Allen Feb. 5, 1957

